1. Technical Field
The present disclosure relates generally to methods for time synchronization of domains, and more specifically, to methods for time synchronization of independent domains based on time information of vehicle.
2. Description of the Related Art
The number and variety of electronic devices installed within vehicles have increased significantly along with the rapid digitalization of vehicle parts. Electronic devices may currently be used throughout the vehicle, such as in a power train control system (including, e.g., an engine control system, an automatic transmission control system, or the like), a body control system (including, e.g., a body electronic equipment control system, a convenience apparatus control system, a lamp control system, or the like), a chassis control system (including, e.g., a steering apparatus control system, a brake control system, a suspension control system, or the like), a vehicle network (including, e.g., a controller area network (CAN), a FlexRay-based network, a media oriented system transport (MOST)-based network, or the like), a multimedia system (including, e.g., a navigation apparatus system, a telematics system, an infotainment system, or the like), and so forth.
The electronic devices comprising each of the above systems are connected via the vehicle network, which supports functions of the electronic devices. For instance, the CAN may support a transmission rate of up to 1 Mbps and may support automatic retransmission of colliding messages, error detection based on a cycle redundancy interface (CRC), or the like. The FlexRay-based network may support a transmission rate of up to 10 Mbps and may support simultaneous transmission of data through two channels, synchronous data transmission, or the like. The MOST-based network is a communication network for high-quality multimedia, which may support a transmission rate of up to 150 Mbps.
The telematics system, the infotainment system, as well as enhanced safety systems of the vehicle, require higher transmission rates and system expandability. However, the CAN, FlexRay-based network, and the like may not sufficiently support such requirements. The MOST-based network, in particular, may support a higher transmission rate than the CAN and the FlexRay-based networks. However, costs associated with applying the MOST-based network in all vehicle networks can be expensive. Due to these limitations, an Ethernet-based network is often adopted as a vehicle network. The Ethernet-based network may support bi-directional communication through one pair of windings and may support a transmission rate of up to 10 Gbps.
Meanwhile, domains supporting a generalized precision time protocol (gPTP) in an industrial system may be classified into universal time domains and working clock domains. The working clock domains may be synchronized with the universal time domain. However, in a case where the working clock domain exists independently without any physical connection with the universal time domain, the working clock domain cannot be synchronized with the universal time domain.